President Barack Obama lamented America’s “slow-rolling crisis”, as National Guard troops were positioned across Baltimore and residents cleaned up after the worst rioting in the port city since the 1968 assassination of Martin Luther King.

In the aftermath of the Monday night violence that followed the funeral of Freddie Gray, a 25-year-old black man who died in police custody from as yet unexplained spinal injuries, the president called for reform and the retraining of police departments. He also advocated a broader push to bring opportunities to deprived communities through education, job training and infrastructure investment.

“This is a slow-rolling crisis that has been going on for some time. This is not new,” he said at a White House press conference yesterday.